Pitman



w. A. JoHNscN PITMAN Filed hAug. 2v. 1941 Dec. 29, 1942.

Patented Dec. 29, 1942 "fg,3os,447

. PrTMAN l Walter A. Johnson, Rochester, Minn. 'v Application August 27, 1941, serial No. 403,477

i 'i sclaims.: (c1. aps-67)] vMy invention relates generally to improvements in pitma'ns for mowers 'and' similar machinery' and more specically to distinct improvements inthe end connections used in such pitmans for' attaching the same to driving and -driven parts'of the mower.

The primary object of the invention isto pro- I vide pitman connections which will permit all required movements and adjustments to be made without interference, and whichare so Constructed 'that convenient attachmentv -and detachment are provided for at the sickle-or knife end'of the pitman Where usually required. Anotherl object is to provide a pitman inwhich provision'is'made for the replacement of worn or broken parts Without removing any bolts or rivets from the bary or beam'of the pitman. Stillfanother Objectis to provide a pitman having end connections 'of such nature that permanent alignment of the bearings ma'yf be maintained and with Wear plates vadapted to take the actual wear, such wear plates being arranged for removal and replacement without destroying (or disturbing otherparts of the con#` nect'ions.

These and other more detailed and specinc ob'- jects will'be disclosed in the course ofthe following specification, reference being com-panying drawing, in which- Fig. l is a plan View of a pitman constructe in' accordance With my invention and showing adjacent parts of the-mower,fincluding a section ofthe knife or sickle and the flywheel.

Fig. 2 is a horizontal cross section, on an enlarged scale, of the sickle or knife connection the pitman'.

Fig. 3 is a section along the Fig. 4 is a enlarged fragmentary section along the line 4-4 in Fig. 1.

Fig. 5 is a section along the line 5-5 in'Fig. 4.

Fig'. 6 is a perspective view of one ofthe` rehad to the acofy line 3 3 in Fig-` 2.

, ed to lie against. the at inner surfaces of the placeable bearing or Wear plates used in the conl nection shown in Figs. 4 and 5. Referring now more particularly and by reference characters to the drawing,`the pitman is designated generally at -A and connects the' flywheel B to the knife head C in such manner as to transform theA` rotary movement of the Wheel Theto a reciprocating movement of the knife. ywheel Bv has an eccentrically located crank pin D to which 'one end of the pitman is connected,

and the'knifehead C, carrying the blades E, hasz.

a'ball F f or connectionto the other end of-th'e pitman. l y

The pitman comprises the usual elongated bar orubeam I9, of/ Wood or 'other suitable material, 5x51 and at opposite ends carries a knife head or cutter connection II and a. crank pin connection I2,

these connections being the subject'matter of -my present invention.

The connection' IIv comprises a pairof yclaspl members or arms I3 and vI4 secured, as by rivets' I5, to' the extended ends 'I6 of flat-springs or spring 'tangs I1 which are riveted at I8 'to opposite sides of the pitman barl I0. Thel extended vor free ends of the clasp members I3 and'y I4 are spaced apart and normally spread by vthey re-` siliency of the springsv I1 to st raddle the ball F, and on their inner faces have concavities or sock ets I9. are provided and have 'flat end `portions 2| adaptclasp members I3 and I4 and concave-convex, bossed ends `22 which are adapted to lie in the aforesaid sockets I9. These ends 22 present inner,

concaved 4andshallow sockets crxbearing's 23 to engage oppositesides of the ball F. Stubs or pilots 24 on the outer convexed sides ofthe bossed ends 22 of thewearplates fit corresponding recesses 25 in Vthe clasp members to properly locate the platesin the sockets I9. Y

The ends 2I of the wear 4plates 20 have apertures 26 which fall in registry with apertures 21 in the clasp members I3 and I4 to receive a draw bolt 28 Which is passedlcrosswise through land 'between the 'clasp members andA which, of course,

aids in properly 'aligning and locating'the-Weari To hold the wear"`plates in place,1espe` f plates. cially when the yclasp members are spread apart,

an expansion spring 29v is coiled around the mid-- 'portion ofthe `bolt 28and bears at its ends against the' wear plates tofhold them atly against inner surfaces of the 'claspmembers y The bolt 28 has a head 3Iliat one end bearing against'on'e` clasp member and at theY opposite' end carries a threaded nut-3I which may be'V turned down to draw the-clasp members together and bring the Wear plates 20to bear on the ball.

` This nut 3I has a diametrically enlarged portion '32 notchedlat 33 to engage the end of a nutflocking spring 34,`which, unless pressed down by hand to'clear the notches, will prevent the nut .from loosening on the bolt. j l' `The clasp members I3 and I4 each have marginal'lips or flanges 35 turnedfinwardly along the upper and lower longitudinal edges of the spring ends I6 to prevent relative twisting of the clasp members and springs, even should the rivets I5 be loosened by Wear and vibration.r

. obviously the construction ofthis knifecn'- nection II-provid-es for convenient replacement-ff- Replaceable bushings or wear plates 29 f of the main wearing parts, the plates 20, without disturbing the clasp members or springs I1, and a supply of the simple and inexpensive wear plates may, of course, be kept on hand for such replacements. Also the sockets 23 may vary in size in various wear plates to t a ball F of any usual diameter. Should the clasp arms themselves become broken they may also be replaced without disturbing the mounting of the springs I1 on the pitman.

The crank pin connection I2 also comprises two clasp members or straps 36-31 which are secured on opposite sides of the pitman bar I by rivets or similar fasteners 38 and which are located on the opposite faces of said bar with respect to the spring tangs I1 to properly angle the connections relative to each other. clasp members 36-31 extend .endwise from the pitman bar and are provided with spaced apertures 39--40 for the reception of two bolts 4I and' 42 as clearly shown, one bolt 4I being located near the ends of the clasp members and the other spaced inwardly therefrom.

The crank pin D of the flywheel B has journaled thereon a bearing or box 43 having a pin receiving bushing 44 and with conventional lubricating means including an oiling connection 45. From one side of this box an ear 46projects having a bore 41 disposed on an axis at right angles to the axis of the crank pinfD and adapted to loosely engage the `outermost bolt 4I, said ear being of such thickness furthermore as to loosely enter and t between the extended ends of the clasp members 36-31.

Wear plates or bearing bushings are again provided for this connection and are designated generally at 48. Each of said Wear plates has spaced openings 49-50 to pass the respective bolts 4I-42. One wear plate 48 is placed against the inner surface of each clasp member 36-31 Where it is held in position by the bolts 4I-42 and the two plates thus mounted are disposed at opposite sides of the bearing ear 46 which is placed over the outermost bolt 4I as aforesaid. The wear plates have projecting bearing bosses I coaxial with the openings 49 which thus may enter into the opposite ends of the bore 41 to provide the actual bearing surfaces for the ear 46, and said bosses taper inwardly toward each other in the direction of the bearing axis to fit the correspondingly shaped, outwardly enlarged ends of said bore. Obviously by drawing the bolt 4I tight the bearing bosses 5I may be forced into the ends of the bore 41 to provide a bearing for the ear 46 and as wear occurs in these parts the bolt may be drawn tighter as required, the clasp arms 36-31 having suflicient resiliency for this purpose. In no case, however, is there any actual bearing contact or wear on the bolt 4I itself. y

Each wear plate 48 further is providedwith a Said lug 52 spaced from the bearing boss 5| and having its face 53, adjacent to said boss, rounded or curved 'substantially on a radius centered at the axis of said boss. The lugs 52` project inwardly from the Wear plates in position to engage and bear against the rounded end of the bearing ear 46 and both this end surface 54 and the engaging surfaces 53 of the lugs are angled to provide for takeup when wear occurs as will be readily evident in Fig. 4.

The bolts 4I-42 have heads 55 engaging one clasp arm and carry castellated nuts 56 on their other ends to engage the otherrclasp member and permit the members t-o be drawn together as described above. The nuts 56 furthermore have rounded ends 51 which fit into and between rounded shoulders 58 formed on outer faces of the clasp members. The bearing thus provided between the nuts and clasp members in combination with the bearing provided both inside and outside of the ear 46, by the bosses 5I and lugs 52, obviously will prevent any relative rocking movement or twisting of the ear 46 between the clasp members, except forthe necessary pivotal movement about the axis of bolt 4 I Uneven wear and looseness will thus be positively prevented.

It will be noted that at each end connection of the pitman the wear is taken by simple and inexpensive Wear plates which are arranged to be conveniently removed and replaced when worn. Also the use of spring material for the tangs I1 prevents crystallization and fatigue in the clasp members I3 and I4 such as to cause breakage when they are spread apart to clear the balll F and similar breakage of the clasp members 36 and 31 at the other vend of the pitman is prevented since they need not be spread to remove the wear plates. It should be unnecessary at any time, therefore, to remove the rivetsfastening the clasp members to the pitman bar I6, which constitutes one of thek most undesirable repairs necessary in 'these machines.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, whaty I claim to be new and desire to protect by Letters Patent is:

1. In a-mower pitman assembly including a bearing box engaging the crank pin and having an apertured bearing ear on one side, means for connecting the pitman and said bearing box comprising spaced clasp members extending from the pitman, a bolt passed through and between the clasp members and extending loosely through the bearing ear, wear plates disposed between vthe clasp members and bearing ear and having openings passing the said bolt, and bearing members extending from the Wear plates into the bearing ear for pivotal engagement therewith.

2. In a mower pitman structure including a bearing box having a bearing ear extending from one side andv said ear having an opening extending from end to end, a pair of clasp members extending from the pitman and disposable in spaced relation to the ends of the bearing ear,

a Wear plate disposed between each clasp member and the adjacent end of the bearing ear, a bearing boss extending from each wear plate into the opening in said bearing ear, and means for detachably securing said wear plates to the clasp members.

3. In a mower pitman structure including a bearing box having a bearing ear extending from one side and said ear having an opening extending from end to` end, a pair of clasp members extending from the pitman andy disposable in spaced relation tothe ends of the bearing ear, a wear plate disposed between each clasp member and the adjacentend ofthe bearing ear, a bearingboss extending from each wear plate into pivotal engagement with the adjacent end of the opening in the bearing ear, a bolt passed j through the clasp members and wear plates and loosely through the said opening in the bearing fear; and another bolt passed through the clasp I5. In a mower pitman structure including a bearing box having* a rounded ear extended from lone side and said ear having a bearing bore',

means for connecting the pitman and bearing box, comprising clasp members secured to the pitman, wear plates detachably connected to the clasp members, bearing bosses on the wear plates adapted to pivotally engage the bore in said bearing ear, and lug members on the Wear platesv adapted/to pivotally engage an outer rounded surface of the bearing ear. Y

' WALTER A. JOHNSON. 

